sPHENIX tracking discussion

["Frawley, Anthony" <afrawley AT fsu.edu>]

Hi All,

Here are my notes from this morning's sPHENIX tracking meeting.

Cheers
Tony

Krista Smith - Effect of intermediate tracker mass on resolution
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Krista showed results of simulations with 3 maps layers + an intermediate tracker layer + TPC.
The intermediate tracker thickness and radius were varied to see the effect on Upsilon mass resolution.

Yasuyuki asked if the simulation included included the internal radiation tail. No it did not. Yasuyuki said he would ask Gaku to provide the code for adding this to the vector meson generator.

Mike McCumber - MAPS and software updates
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Mike said the LANL proponents will get together next week to map out the path ahead now that the LDRD has been funded.
He went over the software projects that need to be completed to improve the realism and performance of the TPC tracking code.

After the TPC work, Mike will return to his effort to implement event pileup in the simulations. He estimated 2 weeks for completion of the pileup modifications. Carlos and Mike are talking about how to collaborate on this.

Tom Hemmick - My last words on the DC idea
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Tom responded to the suggestion that very high occupancy in the proposed DC outer tracker does not matter because high momentum tracks can be separated by waveform analysis. He presented some best case (i.e. overly optimistic) simulations of charge detected in a 2 mm drift region in the DC showing that about 1/3 of the time the high momentum track is missed.

Tom considers that the DC is not viable as an outer tracker for sPHENIX, and he advocated pursuing an interpolating pad chamber as an alternative to the TPC.

Yasuyuki Akiba - EMC-Si Tracker - DC
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Yasuyuki talked qualitatively about the idea of using an inner tracker, the EMC and a DC outer tracker as the sPHENIX tracker. In this proposal the DC is not considered to be a standalone tracker - its purpose is to confirm tracks found by the inner tracker and the EMC, and improve the momentum resolution.

slide 10: Tom commented that this is not the electric field configuration we use - it cannot hold the gain. When built, this voltage configuration was found to be untenable, and we had to find a configuration that worked.

Working on the tools to do a full simulation. Will need a new tracking code, which Gaku is working on.

Gunther commented that it is only 7 weeks until the tracking review. A couple of people commented that it would be a serious mistake to go into the tracking review with any tracker proposal that is not fully understood before the review. Ultimately, the collaboration will have to decide what is presented at the review.